Spanish cyclist Luis Leon Sanchez rode to victory in the 14th stage of the Tour de France on Sunday, giving a welcome boost to his stricken team.

Sanchez, whose team has been decimated by crashes, had been part of an 11-man break which built a 16-minute lead on the peloton well before the end of the 191 km stage from Limoux to Foix.

And after counter-attacking Frenchman Sandy Casar on the 38 km descent towards the finish, the Spaniard made a decisive move with just over 11 km to race.

Sanchez went on unchallenged to finish 47sec ahead of Slovakian Peter Sagan (Liquigas) with FDJ rider Casar in third and the main peloton, including race leader Bradley Wiggins, coming over the finish 18 minutes in arrears.

"I started the day with victory in mind but given the company I was in I knew I'd have to attack from far out to have any chance," said Sanchez, whose team has only four remaining members from the nine starters.

Although the early breakaway had built a significant lead that never looked under threat, they were given further room by the dramatics going on in their wake – and which showed Wiggins' sense of fair play.

Defending champion Cadel Evans started the day 3min 19sec adrift but could have finished it far worse off after falling victim to several mechanical problems that left his hi-tech BMC team looking amateurish.

It later transpired that "one or two" spectators had thrown nails on to the road, causing a rash of punctures among the 50-strong chasing group according to race director Jean-Francois Pescheux.

First, the Australian was left waiting at the summit of the last, brutal climb, the Peguere, for nearly two minutes after suffering a problem with his back wheel.

Looking flustered and gesturing in despair as he held his bike minus its back wheel, he got a replacement from a team-mate only to require another wheel change on the descent, during which time the yellow jersey peloton had sat up and waited.

Even Wiggins had to change bike, the Englishman signalling to his team car to stop as he got a quick replacement.

It left Evans in a desperate chase with his BMC team to catch Wiggins' leading group, and he was glad once he did.

Pescheux later explained: "One or two spectators had thrown nails on to the road, we don't know why, but there were around 30 punctures altogether."

"The nails were mainly thrown on the ground around 200 metres from the summit.

"At the end, some riders ended up with two or three nails in their tyres."

Wiggins, who took the yellow jersey after stage seven last Saturday, will take a 2:05 lead over teammate Chris Froome into Monday's mainly flat stage from Samatan to Pau.

Italian Vincenzo Nibali (Liquigas) is still third overall at 2:23 with Evans still fourth at 3:19.